Adjustable preforming head



Feb. 14, M950 O, A MCNAMEE 2,497,178

. ADJUSTABLE PREFORMING HEAD Filed NOV. 2, 1948 Patented Feb. 14, 1950 ADJUSTALE PREFORMING H EAD Owen A. McNamee, Worcester, Mass., assignor to The American Steel and Wire Company of New Jersey, a corporation of New Jersey Application November 2, 1948, Serial No. 57,850

. 1 I The invention relates to a preforming head for wire-stranding or cable-armoring machines.

The preforming of wires as they are laid around` a core to form a strand or around an insulated conductor or cable to form an armor sheath thereon has long been common practice and various types of preforming heads have been devised. The ability to vary the radius and pitch of the helix vto which the wires are preformed is highly desirable and this has led to the provision of adjustable preforming heads. One of those with which I am familiar utilizes a Worm and wormwheel drive for circumferentially adjusting one of the three or more bevel-edge plates mounted in spaced relation along the axis of the laying machine with bending rollers spaced circumferentially therearound, which constitute the usual preforming head, to the desired angular position relative to the other plates. This varies the radius of the helix. Screws are also provided for adjusting the plates axially to vary the pitch of the helix. I

The construction of known adjustable preforming heads described above is bulky and limits the minimum axial spacing between the bending rolls journaled radially on the beveled edges of adjacent plates, as well as the minimum radial dimension of the head. The result is that adjustable heads of known types are adapted only for preforming wires on large cores and cannot be made for preforming fine wires laid over small cores. In addition, the worm and worm-wheel adjusting means tends to creep under vibration and frequent checking and resetting are neces-V,

sary to maintain the desired adjustment. The mounting oi the roll-supporting plates lacks rigidity, furthermore, and the adjustment becomes progressively less exact with wearV of the parts.

I have invented an improved preforming head having novel means for adjusting the middle plate angularly relative to the others and positively locking it in position so as to maintain precisely the desired setting thereof despite vibration or wear. The adjusting means is extremely simple and compact so it may be incorporated in heads of small size thus making possible the use of adjustable heads for stranding ne wires about a small core. In a vpreferred embodiment of my' improved head, I provide a middle plate lcomposed oi a disc having a ring rotatable there-j around to support the bending rolls. The disc has a segment cut out therefrom and a block is mounted on the'disc having opposite faces exposed in the cut-out. Adjusting screws threaded through the ringengage said faces and serve tol rotate the ring on the disc and hold it in adjusted position. The faces of the block are preferably;

inclined outwardly toward a radius from the center of the disc through the block. The head also includes two outer plates, fixed against rotation relative to the stranding machine, one on either side of the angularly adjustable plate. All the plates are adjustable axially, being secured to the spindle of the stranding machine by set.

screws.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating a preferred embodiment. In the drawings,

Figure l is a side elevation of my improved preforming head, partly in axial vertical section;

Figure 2 is a front elevation of the angularly adjustableA plate, i. e., the intermediate plate in Figure l partly broken away and with parts in section;

Figure 3 is a sectional view through the intermediate plate of the head taken along the line III-III of Figure 2; and

Figure 4, is a partial diagrammatic plan View showing the effect of the angular adjustability of the middle plate on the radius of the helix.

Referring now in detail to the drawings, the

delivery end ofthe hollow spindle of a machine for laying wire around the core of a strandor a.V

cable to be armored is indicated at I8. The preforming head of my invention, indicated generthe core or cable and drawn through the closing die (not shown). The rollers I5 are journaled on radial stub shafts I5a disposed normal to the beveled edgesV of the plates. The axial adjustment of the Vplates relative to each other permits the pitch of the helices to be varied as desired. To permit adjustmentkof the radius of the helices, it is necessary to turn the intermediate plate I3 on the spindle relative to the other plates and it is to means for accomplishing this that my inven-'- tion relates in particular.

The plate I3 comprises a disc I1 and a ring I8 rotatable thereon. To facilitate rotation. the disc has a peripheral groove I9 and the ring carries anti-friction means such as balls 20 traveling in the groove which serves as a race. To accommodate the balls 20 the ring I8 is drilled radially at circumferentially spaced points and fitted with plugs 2I threaded into the resulting holes to hold the balls in place and permit the proper adjustment thereof.

As best shown in Figure 2, the disc I1 has a portion of its edge milled off to form a segmental cut-out 22. The cut-out is recessed. Centrally, aS indicated at 23, to accommodate an abutment in the form of a pyramidal block 24 fitting snugly therein. The block has a stud 25 projecting from the base thereof which is received in a hole drilled centrally in the recess 23. The block 22 has two parallel sides coplanar with the faces of the discs I1 and two inclined faces 26. The shape of. the block in elevation is substantially that of an isosceles triangle and it is disposed, as shown, with its base normal to a radius of the disc drawn through the vertex. This vertex 21 is slightly flattened and has sliding engagement with the inner periphery of the ring I8.

Adjusting screws 28 are threaded into tapped holes in the ring I8. These holes are at an angle to each other but are not exactly radial. The screws engage the sloping faces of the abutment or bearing block 24' and rigidly secure the ring I8 in predetermined angular relation to the disc IT. An adjustment of this relation may easily be made by backing off one screw and turning down the other. It will be understood that only a relatively limited range of angular adjustment is necessary. In order to indicate the exact angular relation of the disc and ring, I provide an arcuate scale 28 on the disc I1 graduated in degrees and an index 3Q on the ring I8 cooperating therewith. It will be apparent that the desired adjustment of the ring relative to the disc may be made quickly and easily. When it has been made and both screws again turned firmly against the block 24, the assembly is positively held in adjusted relation against any possibility of shifting in service as a result of wear, yvibration or the like.

The principal advantage Vof the invention is its simplicity of structure and the resulting compactness whereby the necessary parts may be designed for the smaller sizes of preforming heads for which adjusting means previously known are not adapted. The invention thus makes it possible to gain the benefit of adjustable preforming on smallstrands or armor for small cables. The invention also has the advantage that the angular adjustment of the intermediate plate may be made with great precision and maintained during service despite wear and vibration, as already pointed out.

The adjustable intermediate disc is mounted directly on the spindle of the stranding machine. This contributes toa rigid mounting. The full pitch of the helices along Vthe spindle is available for seating the plate giving a large bearing surhas occurred. The ring is held firmly in correct position on the disc by the bearing balls which thus maintain the rollers rigidly in proper position yet permit easy adjustment. The triangular shape of the bearing block inoreasesthe .exacte ness of adjustment beyond that ordinarily 4result face which holds the adjustment .even after wear ing from the' use of screws. The angular relation of the screws causes them to lock against loosening under vibration.

Although I have illustrated and described only a preferred embodiment of the invention, it will be recognized that changes in the details and arrangement of the parts thereof .may be made Without departing from the principle of the invention or the scope of the appended claims.

I claim:

1. In a preforming head for a wire-stranding machine a generally circular plate adapted to be mounted on the spindle of the machine for supporting wire-bending rollers spaced about the periphery thereof, said plate comprising a central disc, a ring surrounding the disc and rotatable thereon, said disc having a segmental cut-out in its periphery, a block mounted on said disc having opposite lateral faces exposed in said cut-out, and adjusting screws threaded through said ring and adapted to engage said faces.

2. The apparatus defined by claim 1 characterized by said faces sloping outwardly toward a radius from rthe center of the disc through said block.

3. The apparatus defined by claim 1 characterized by said block having a surface slidably engaging the inner periphery of said ring.

4. The apparatus defined by claim 1 characterized by said disc having a recess in said cut-out, said block fitting snugly in said recess.

5. The apparatus dened by claim 1 characterized by one of said disc and ring having a peripheral race, and anti-friction means carried by the Aother and adapted to travel on said race.

6. The apparatus defined by claim 1 characterized by said block having -the shape in side elevation of an isosceles triangle and having its base normal to a radius of the disc drawn through the vertex of the block.

7. In a preforming head for a wire-stranding machine, a generally circular plate adapted to be mounted on the spindle of the machine vfor supporting wire-bending rollers spaced about the periphery thereof, said plate comprising a central disc, a ring surrounding the dise and rotatable thereon, a pair of adjusting screws extending through the ring at an angle to eachother, and an abutment on said disc adapted to be engaged by both said screws.

8. The apparatus defined by claim '1 characterized by said abutment having oppositely sloping faces generally normal to said screws and adapted to be engaged thereby.

9. The apparatus defined by claim 7 characterized by said abutment being separate from the disc and said disc being cut out to receive the abutment.

10. The apparatus defined by claim 9 characterized by said abutment having a stud projecting inwardly therefrom, said disc having a hole therein toreceive said stud. Y

11'1. The apparatus defined by claim 7 characterized by said abutment being of triangular shape in side elevation and disposed with its base generally normal to the radius of the disc drawn through the vertex ofthe abutment.

12. The apparatus defined by claim '7 characterized by .anti-friction means carriedby one of said disc and ring and a circumferential race in the other with which said means cooperate.

`OWEN A. McNAMEE.

No references cited. 

